NASA's Mars rover Curiosity cut a wheel scuff mark into a wind-formed ripple at the "Rocknest" site to give researchers a better opportunity to examine the particle-size distribution of the material forming the ripple.

Spring time on Mars: Nasa's Rover Opportunity wakes up from winter sleep to incredible view over misty blue Endeavour crater

Nasa's Mars Rover Opportunity captured a spectacular view of the Endeavour crater and sent the image back to Earth. Endeavour is the largest impact crater the rover has explored in its eight-year mission.

These rounded pebbles got their shapes after polished in a long-ago river in Gale Crater. They were discovered by Curiosity rover at the Hottah site.

Layers at the Base of Mount Sharp. A chapter of the layered geological history of Mars is laid bare in this postcard from NASA's Curiosity rover. The image shows the base of Mount Sharp, the rover's eventual science destination.

This sweeping view by ESA’s Mars Express extends from the planet’s south polar ice cap and across its cratered highlands to the Hellas Basin (top left) and beyond. - Credit: ESA/DLR/FU Berlin, CC BY-SA IGO

This look back at a dune that NASA's Curiosity Mars rover drove across was taken by the rover's Mast Camera (Mastcam) during the Martian day, or sol, of Curiosity's work on Mars (Feb. [Read the full story here.